(a) Field of the Invention
The present invention relates to a pinhole detection system of a fuel cell. More particularly, the present invention relates to a pinhole detection system of a fuel cell that detects a pinhole formed inside a fuel cell stack element, especially MEAs and bipolar plates.
(b) Description of the Related Art
Generally, a fuel cell system generates electrical energy from chemical energy.
A fuel cell system includes a fuel cell stack that generates electrical energy, a fuel supply system supplying fuel (hydrogen) with the fuel cell stack, an air supply system supplying oxygen of air, which is an oxidizing agent that is necessary for electrochemical reaction of the fuel cell stack, and a heat and water management system that controls the operating temperature and the moisture of the fuel cell stack.
Preferably, the fuel cell stack is made by stacking three layers of membrane-electrode assembly (MEA), two gas diffusion layers (GDL), and a bipolar plate, alternately.
However, MEA and bipolar plate of a pinhole can be formed during making process for fabricating the MEA and pressing process for fabricating the bipolar plate in each. Further, as the MEA and the GDL are joined (or hot pressed) to improve productivity, a pinhole can be formed through an electrolyte membrane of the MEA by carbon fiber of the GDL.
The pinhole of the MEA and the bipolar plate generates a burning phenomenon by the chemical reaction of oxygen and hydrogen to meet each other directly and pollution phenomenon of the MEA by leakage of antifreeze, such that output performance of the fuel cell stack and durability are decreased and the fuel cell stack can be shut down.
Accordingly, there is a need in the art to inspect the fuel cell stack for a pinhole to improve the quality of the fuel cell stack. Further, there remains a need in the art to inspect a pinhole, which is formed inside the stack element.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.